[chore] Add clo monitor exemption for artifact hub (#3772)

Author: thompson-tomo

.clomonitor.yml

@@ -0,0 +1,6 @@
+# Copyright The OpenTelemetry Authors
+# SPDX-License-Identifier: Apache-2.0
+# see https://github.com/cncf/clomonitor/blob/main/docs/checks.md#exemptions
+exemptions:
+  - check: artifacthub_badge
+    reason: "Artifact Hub doesn't support c++ packages"